Thanks for the input, Morris. I've been using external drives for over a year, both USB and Firewire, without a hiccup (well, one or two, but it's very rare and very brief). So that is not an issue as far as I'm concerned. I've been using Lacie D2 Extreme drives and the noise has not been an issue for me, though it is there it's pretty minimal. There have been some reports of drive failure, especially with the cheaper Lacie drives. My good friend had an Extreme drive fail on him. I've had good luck with them as have a few other friends. There are no guarantees, as I'm sure you are aware. The OWC (Other World Computing) Mercury Elite Pro drives have a good reputation, but the one I've heard is pretty loud, and I don't think they have an Ethernet version (they actually sell Lacie's drives for that).
As far as the Ethernet drive, again, thanks for that input. You certainly may have something there. There is, I think, one difference in that, and correct me if I am wrong, Airport Express uses the 802.11B convention, while my Aiport Base Station and Airport Extreme card stream info in 802.11G which is significantly faster. This is why it would be helpful to get input from someone doing exactly what I am proposing to do. So let me know if I'm off base, but there is that difference.
Thanks again for this, and any further input.
Marco